I tried different dosages over a year and found that 1mg worked better than 2mg (and 2mg worked better than 3mg). All worked better than nothing, but I was working nights and getting virtually no sun, so your mileage may vary.
Yes, I've seen that sort of reaction a lot. I originally used 3mg and went down to 1.5mg because it seemed to be working better. I recently ordered a bunch of 1mg pills which I'm going to turn into placebo capsules and capsules dosing from 0.25 to 1.5mg and try seeing what doses work best for me.
Thus spake Eliezer:
It seems that many here might have outlandish ideas for ways of improving our lives. For instance, a recent post advocated installing really bright lights as a way to boost alertness and productivity. We should not adopt such hacks into our dogma until we're pretty sure they work; however, one way of knowing whether a crazy idea works is to try implementing it, and you may have more ideas than you're planning to implement.
So: please post all such lifehack ideas! Even if you haven't tried them, even if they seem unlikely to work. Post them separately, unless some other way would be more appropriate. If you've tried some idea and it hasn't worked, it would be useful to post that too.